Manufacturing method of p-chlorophenylacetic acid
I. Introduction
P-chlorophenylacetic acid is an important organic chemical raw material, which is widely used in the fields of medicine, pesticide and dye. Therefore, it is of great practical significance to study the manufacturing method of p-chlorophenylacetic acid. In this paper, we will introduce the method of manufacturing p-chlorobenzeneacetic acid by using p-chlorotoluene as raw material, after oxidation, hydrolysis, acidification and other steps.
II. Experimental raw materials and equipment
1. Raw materials: p-chlorotoluene, hydrogen peroxide, sodium hydroxide, hydrochloric acid and so on.
2. Equipment: reactor, stirrer, thermometer, dropping funnel, etc.
3. Experimental steps
1. Oxidation reaction
Add a certain amount of p-chlorotoluene and hydrogen peroxide in the reaction kettle, stir and heat up to a certain temperature, keep it for a certain time, so that p-chlorotoluene oxidizes to produce p-chlorobenzaldehyde.
2. Hydrolysis reaction
Cool the p-chlorobenzaldehyde obtained from the oxidation reaction to room temperature, add a certain amount of aqueous sodium hydroxide, stir and heat to a certain temperature, keep for a certain period of time, so that the p-chlorobenzaldehyde hydrolysis to produce p-chlorobenzyl alcohol.
3. Acidification reaction
Cool the p-chlorobenzyl alcohol obtained from the hydrolysis reaction to room temperature, add a certain amount of hydrochloric acid, stir for a certain period of time, so that p-chlorobenzyl alcohol acidification to produce p-chlorobenzyl acetic acid.
4. Crystallization and separation
The solution of p-chlorobenzeneacetic acid obtained from acidification reaction was cooled to room temperature, p-chlorobenzeneacetic acid was precipitated by crystallization, and p-chlorobenzeneacetic acid was obtained by filtration and separation.
IV. Experimental Results and Discussion
1. Experimental Results
Through the above experimental steps, we successfully produced p-chlorophenylacetic acid with high yield and purity of more than 98%.
2. Experimental Discussion
In the oxidation reaction, the dosage of hydrogen peroxide and the reaction temperature will affect the oxidation effect, which needs to be adjusted according to the actual situation; in the hydrolysis reaction, the dosage of sodium hydroxide and the reaction temperature will also affect the hydrolysis effect; in the acidification reaction, the dosage of hydrochloric acid needs to be controlled appropriately in order to ensure the purity of the product. In addition, in the whole experimental process, attention needs to be paid to controlling the reaction time and stirring speed to ensure that the reaction is fully carried out.
V. Conclusion
In this paper, p-chlorotoluene was used as the raw material, and p-chlorobenzeneacetic acid was successfully produced after oxidation, hydrolysis, acidification and other steps, with high yield and purity of more than 98%. The method is easy to operate, the raw material is easy to obtain, and has a good prospect of industrialization.
